package com.mycompany.mypro;

import com.alibaba.fastjson.JSON;
import com.alibaba.fastjson.JSONObject;

public class App2 {
    public static void main(String[] args) {
        String jsonString = "{\"password\":\"123456\",\"username\":\"dmego\"}";
        JSONObject jsonObject = JSON.parseObject(jsonString);
        jsonObject.put("password", "123");
        jsonObject.put("username","zzz");
        String json = JSON.toJSONString(jsonObject);
        System.out.println(json);
    }
}